The overall goal of this research is to advance understanding of a critical but unstudied aspect of motor skill acquisition-how children learn about hidden affordances for action. Previous work has focused on children's discovery and implementation of overt affordances such as reaching for objects and squeezing through apertures. Information for overt affordances is readily available through visual and haptic exploration. In contrast, information for affordances of many everyday artifacts is hidden, and requires discovery and implementation of a non-obvious target action. How do young children discover that the graspable cap of a container requires a twisting action or that a closed door requires a pushing or pulling action to open it? Indeed, the closures on artifacts used for self-care, opening cabinets and doors, and so forth require an array of nonobvious actions, but little is known about how children discover and implement the hidden affordances that permeate activities of daily living. We hypothesize two ways that young children can learn about hidden affordances-through the same types of do-it-yourself learning that characterize learning about overt affordances and/or through socially supported learning provided by knowledgeable adults. We will test whether children can discover and implement hidden affordances through (AIM 1) do-it-yourself learning and (AIM 2) socially supported learning across a range of closure types reflecting several activities of daily living (opening containers, flexible pouches, cabinets and doors). We will describe which actions children spontaneously generate and how learning unfolds in real time and across development. Inspired by mothers' natural social support of children's actions, we will test the effectiveness of various types of affordance-specific social information by systematically varying social support and asking how these manipulations affect children's discovery and implementation of the target action. We will characterize when and why children seek social support from adults, and use head-mounted eye tracking to determine whether children direct their visual attention to critical information offered by an adult. Finding on children's do-it-yourself learning about hidden affordances will have implications for designing closures that enable children to perform activities of daily living and for ensuring children's safety by limiting their access to dangerous substances and situations. Findings on socially supported learning will have implications for how parents, teachers, and occupational therapists can help children to perform activities of daily living independently.